Actinospermum uniflorum (Nutt.) Barnhart (original description)
Antennaria campestris Rydb. accepted as Antennaria neglecta Greene (original description)
Antennaria microphylla Rydb. (original description)
Antennaria rosulata Rydb. (original description)
Antennaria solitaria Rydb. (original description)
Antennaria umbrinella Rydb. (original description)
Arnica gracilis Rydb. (original description)
Arnica pedunculata Rydb. accepted as Arnica fulgens Pursh (original description)
Artemisia candicans Rydb. accepted as Artemisia ludoviciana subsp. candicans (Rydb.) D.D.Keck (original description)
Artemisia floccosa Rydb. (original description)
Aster camptosorus Small accepted as Symphyotrichum shortii (Lindl.) G.L.Nesom (original description)
Carduus lecontei (Torr. & A.Gray) Pollard accepted as Cirsium lecontei Torr. & A.Gray (original description)
Carduus nuttallii (DC.) Pollard accepted as Cirsium nuttallii DC. (original description)
Chrysopsis ruthii Small accepted as Pityopsis ruthii (Small) Small (original description)
Coleosanthus wootonii Greene accepted as Brickellia lemmonii var. lemmonii A.Gray (original description)
Crepis runcinata var. alpicola Rydb. accepted as Crepis runcinata (E.James) Torr. & A.Gray (original description)
Erigeron angustifolius (A.Gray) Rydb. accepted as Erigeron glacialis var. glacialis (original description)
Erigeron condensatus (D.C.Eaton) Greene accepted as Erigeron concinnus var. condensatus D.C.Eaton (original description)
Erigeron minor (Hook.) Rydb. accepted as Erigeron lonchophyllus Hook. (original description)
Erigeron montanensis Rydb. accepted as Erigeron ochroleucus Nutt. (original description)
Erigeron oblanceolatus Rydb. accepted as Erigeron glabellus var. glabellus Nutt. (original description)
Erigeron subcanescens Rydb. accepted as Erigeron caespitosus Nutt. (original description)
Eupatorium hyssopifolium var. angustissimum C.Mohr accepted as Eupatorium hyssopifolium L. (original description)
Eupatorium petaloideum Britton ex Britton accepted as Eupatorium album L. (original description)
Filago nivea Small accepted as Diaperia verna (Raf.) Morefield (original description)
Gaillardia multiceps Greene (original description)
Kuhnia kuhnia (Gaertn.) C.Mohr (original description)
Machaeranthera linearis Greene accepted as Dieteria canescens var. glabra (A.Gray) D.R.Morgan & R.L.Hartm. (original description)
Ratibida peduncularis (Torr. & A.Gray) Barnhart (original description)
Ratibida pinnata Barnhart (original description)
Ratibida tagetes (E.James) Barnhart (original description)
Sonchus filipes A.Heller (original description)